PROJECT SUMMARY/ABSTRACT Alcohol misuse among college students is a national public health concern and remains a top priority for NIAAA. To facilitate prevention and intervention efforts, it is critical to gain understanding of the psychosocial etiology underpinning college student alcohol use. There is strong evidence that social norms (i.e., perceptions of peers? alcohol-related attitudes and behaviors) are among the most robust predictors of students? alcohol use. This normative influence may be particularly strong within the small proximal peer groups that students belong to, such as student clubs and organizations. Given that several large national surveys have indicated that over 70% of American college students join a formal club or organization, these groups represent a promising platform for prevention and intervention, but they are currently understudied. The central objective of this research is to better understand students? adherence, or conformity, to the group drinking norms of their student clubs. Specifically, this project seeks to answer three questions: Aim 1) Which students are more susceptible to normative group influence, and which groups promote greater norm adherence among members? Aim 2) What is the longitudinal direction of the association between perceived group drinking norms and members? alcohol use? and Aim 3) Do group members obtain socially desirable outcomes (e.g., popularity) when they adhere to the drinking norms of their group? To address these novel research questions, the applicant will collect longitudinal data (3 waves; N=350), using a social network design, from 25 collegiate club sport teams. The applicant will employ social network analysis (SNA) to capture objective, sociometrically derived indices of group structures (i.e., density) and identify where each member sits within respective groups? status hierarchy (i.e., centrality), to test whether these network indices amplify or depress the association between perceived group drinking norms and student alcohol use (Aim 1). Longitudinal structural equation modeling will be used to identify whether perceived group drinking norms predict alcohol use (conformity), alcohol use predicts perceptions of group drinking norms (projection), or this association is temporally reciprocal (Aim 2). Finally, the applicant will compute an empirically derived measure of correspondence between group drinking norms and alcohol use (i.e., norm-adherence) by extracting person-specific slopes generated from multilevel models and using multilevel negative binomial regression to test whether norm adherence across time predicts social acceptance and status within the group (Aim 3). By uncovering the nature of normative influence in small groups, the findings from this project represent a paradigm shift in social norms research and are well-suited to generate insights about how to redesign alcohol prevention strategies to target modifiable aspects of small groups. Under a team of expert mentors (Drs. Blair Evans, Rob Turrisi, Nancy Barnett, Jason Kilmer, and Bethany Bray), this fellowship will provide necessary theoretical, methodological, and professional training to aid the applicant?s development into an independent research scientist.